The present invention relates to a tremolo unit for an electric guitar.
An electric guitar that has a tremolo unit prevents the electric guitar from being off-key by changes in the tension (pitch) of strings while playing the guitar using the tremolo unit. U.S. Patent Publication No. 4,171,661 discloses an electric guitar that has a tremolo unit. According to the guitar of the above publication, each string is locked by a bolt and a pressing member at a saddle of the tremolo unit. A fixing member is also arranged on a nut in the vicinity of a head to fix the strings. This prevents the guitar to be off-key even when using the tremolo unit.
However, when the strings are locked with the nut, tuning of the strings with tuning pegs is difficult. Therefore, a fine-tuning device is provided on the saddle to permit the guitar to be fine-tuned even after the strings are locked with the nut. The tremolo unit also includes harmonic tuning means, which adjusts the position of a contact point of the strings at the saddle portion in the tuning direction.
FIG. 10 illustrates a tremolo unit that has harmonic tuning means. The tremolo unit is mounted on the body 12 of a guitar and includes a base plate 23, which is supported at the upper portion of the body 12 with hinge mechanisms 22 (only one is shown) such that the base plate 23 can be rotated up and down. Saddle holders 35 (only one is shown) are supported by the base plate 23 such that the saddle holders 35 can be moved forward and backward. Each saddle holder 35 corresponds one of the strings 15 (only one is shown) of the guitar. A saddle 37 is supported by each saddle holder 35 with a pin 38 such that the saddle 37 can be rotated up and down.
Each saddle 37 supports a pad 39, which clamps the corresponding string 15. A string fixing bolt 40 is threaded into each saddle 37. Thus, the string fixing bolt 40 presses and clamps the string 15 with the clamp pad 39. Fine-tuning bolts 42 are threaded into the rear end 230 of the base plate 23. When each fixing bolt 40 is moved up and down with the corresponding fine-tuning bolt 42, force is transmitted to the saddle 37 through the pad 39. This rotates the saddle 37 about the corresponding pin 38. Accordingly, the associated string 15 is fine-tuned.
Harmonic tuning bolts 49 are inserted through pin supports 35e formed at the rear end of the base plate 23. A threaded hole 61 is formed in the rear end of each saddle holder 35. The distal end of each harmonic tuning bolt 49 is threaded into the corresponding threaded hole 61 to adjust the forward and backward position of the associated saddle holder 35. Accordingly, the harmonic of the associated string 15 is tuned.
However, according to the above mentioned tremolo unit, the harmonic tuning bolts 49, which move the saddle holders 35 forward and backward, are located at a position lower than the top surface of the body 12. Therefore, to rotate any of the harmonic tuning bolts 49, the base plate 23 is rotated counterclockwise about the hinge mechanisms 22 by a certain amount using a tremolo bar (not shown). That is, the harmonic tuning bolt 49 needs to be moved to a position above the body 12 before being rotated. Therefore, the harmonic tuning operation is troublesome.
Furthermore, when the base plate 23 is rotated, the position of each saddle holder 35 is changed by force transmitted through the associated bolt 49. This rotates the saddle 37 and thus changes the pitch of the corresponding string 15.